1. Field of the Invention
The present invention relates to a device for use in the assembly of horizontal blinds and, more particularly, to a button for securing the string ladder to the bottom rail of a horizontal blind assembly without the use of a grommet.
2. Discussion of the Related Art
Horizontal blinds are provided with two, and frequently as many as three or four string ladders which extend down from the control mechanism in the headrail to a bottom rail. The string ladders are used to support the horizontal slats of the horizontal blind assembly in spaced relation to one another, while allowing tilting and lifting of the horizontal slats upon manipulating the string ladders using the controls (e.g. cords and/or twist rods) connected to the control mechanism.
In the manufacturing of horizontal blinds, the assembly of the horizontal blind components is performed entirely by hand, requiring approximately one hour of labor. In particular, securing the string ladders to the bottom rail during the manufacturing and assembly of horizontal blinds has been found to be a tedious and time consuming task. All prior art methods have used a metal grommet which is crimped in order to secure the ends of the ladder strands. More specifically, the ladder strands at the bottom of the assembly are passed around the front and rear edges of the bottom rail and are secured on the underside of the bottom rail using the grommet. To do this, the free ends of the ladder are threaded through the grommet and the grommet is pulled up the ladder against the underside of the bottom rail until the bottom rail is held at the desired level. Next, the grommet is crimped to lock the grommet in place by pinching the ladder strands, thereby holding the bottom rail at the desired level on the string ladder. The loose ends of the string ladder, below the grommet, are then cut and discarded. Finally, one of various cover devices is fitted to the bottom rail in order to conceal the grommet and cut ends of the string ladder.
In the past, various devices have been provided for concealing the grommet and cut ends of the string ladder of assembled horizontal blinds. For instance, snap-on band devices, often referred to as xe2x80x9ctape locksxe2x80x9d are well known and used on many old style bottom rails which have a generally rectangular cross-sectional configuration. More recent designs of bottom rails incorporate a generally trapezoidal cross-sectional configuration which does not allow snap attachment of tape locks. This has lead to the development of other devices which plug into a countersunk bore formed on the underside of the modern design bottom rail. One such plug device well known in the industry incorporates a hollow tubular member with a flared bottom. In use, the ends of the ladder are passed through the tubular member and the grommet is secured at the desired location. The plug is then inserted into a hole in the underside of the bottom rail and the ladder is pulled up to move the grommet into concealed position within the tubular member. This device is often referred to as a xe2x80x9cMexican hatxe2x80x9d due to its configuration. Another device, referred to as a xe2x80x9cbutton,xe2x80x9d snaps into place within the countersunk bore formed in the underside of the bottom rail to conceal the grommet and cut ends of the ladder strands. This button device, also well known in the industry, does not incorporate a through hole. Therefore, it is necessary to bunch up the end of the string ladder and the grommet, for concealed capture within the button, prior to securing the button to the bottom rail. This process has proven to be time consuming and tedious, adding to the labor time necessary to manufacture a horizontal blind assembly. All of the above-described devices and methods of securing a string ladder to the bottom rail of a horizontal blind assembly require the use of a metal grommet, which increases the labor time and cost in the manual assembly process.
Accordingly, there is an urgent need in the horizontal blind industry for a device which easily and quickly fastens to the bottom rail of a horizontal blind assembly to secure the lower end of the string ladder to the bottom rail in the manufacturing and assembly process.
The present invention is directed to a device for securing a string ladder to the bottom rail in a horizontal blind assembly. More particularly, a button includes a base plate with a central hole and a tubular stem extending upwardly from the base in axial alignment with the central hole for passage of strands of the string ladder therethrough. Arcuate wall segments spaced radially outboard of the central tubular stem are provided with a top beveled edge and longitudinal compression ribs to promote insertion and snug-fitted captured receipt within a countersunk bore in the underside of the bottom rail in order to fasten the button to the bottom rail. Opposing teeth spaced between the arcuate wall segments provide slots for passage and wedged grasping of the ladder strands when the button is fastened to the bottom rail.